The present invention relates to an aperture setting device applicable, for example, to a drawing die, a chuck and so forth, and more particularly to an aperture setting device in which the size of a predetermined polygonal aperture can be changed, retaining the polygonal configuration.
Heretofore, there has been employed a guide device of a conical, unitary structure for guiding an electric wire or the like to a predetermined position. In the prior art, since it is difficult to change the size of the conical structure without introducing a gap between adjacent elements forming the conical structure, use is made of a guide device of a size corresponding to the thickness of each electric wire or the like to be guided. Also there has been employed a chuck of the type clamping an article with three or four clicks. In the conventional chuck of this kind, the article to be clamped may get between the clicks according to the size of the article, sometimes resulting in a state in which the axis of the chuck is not in agreement with the axis of the article. Accordingly, for example, machining of the article cannot immediately be carried out on the basis of the axis of the chuck in some cases.
In the past, there has not been put to practical use a device which is capable of changing with a simple arrangement, a polygonal aperture into various sizes continuously or stepwise, retaining it on the same axis. Such a device, if realized, would be of great ability when employed in such devices as a chuck, a press tool, an electric wire guide device, a drawing die, a control valve and so forth.
It is an object of the present invention to provide an aperture setting device which is capable of easily changing the size of a predetermined polygonal aperture with a simple arrangement.